I would do it! The remaps are generally what the car should be from manufacturer! They are de-tuned to take in to account, poor fuel, poor servicing, extreme climates, poor owners!
This is why also, most find after a remap, especially on a diesel, the mpg actually goes up!
your old B7 would have had the early DPFs, which because the engine were not originally designed for, they gave issues, remapped or not! DPFs don't like short journeys and want a good long journey from time to time to keep them happy.
It's all relative, yes the remap makes your engine give more power, but this doesn't mean parts will wear out faster or prematurely. Thrash your car around and that will wear things and reduce service intervals, remap or not! So unless your thrash your car everytime you drive it and all the time, the reliability or life of parts will be the same with or without a remap. Your service indicator will reduce the miles to next service if you drive hard. So treat it well and reduce the service intervals by about 25% and it will give you the same life out of the car as without a remap.
I had an B6 A4 1.9 tdi avant, that at 72k miles, the gearbox went. Luckily I'm handy with tools, so £100 and a new 1st/2nd gear syncro ring later, it was fixed. Then I had a remap done and did about 30k miles more with no probs! Sold it in 2015 after 9 years ownership and last time I checked the MOT history, it had 240k miles on it! It also returned 72mpg average! Some say those 1.9 PD engines were the best, the cam was a 'soft' point so needed to use the proper engine oil. Seen 1.9s with 600bhp!
Basically a remap will up the power by about 40bhp, so the car will take it so long as you don't abuse it, but that said, not having the remap won't guarantee it won't die if you abuse it.
Had my A5 3.0tdi remapped to 310bhp and it was fine for 4 years when I sold it and got my S5, remapped that and got 480bhp!
Remaps will keep everything within the limits and tolerances, like EGTs, timing, boost, fuel, so they are quite safe, so long as they are performed by a decent company. Even cheap 'generic' remaps come from the bigger remap brand companies, as little remap companies will just buy off the shelf remaps. Nothing wrong with that, they generally just give slightly less power as the limits are pulled back a bit to increase the safety margin when applied to numerous cars that are not dyno mapped.